AZEOTROPE OR AZEOTROPE-LIKE COMPOSITIONS OF TRIFLUOROIODOMETHANE (CF3I) AND 1,1,1,2,2,3,3,-HEPTAFLUOROPROPANE (HFC-227ca)

ABSTRACT

The present disclosure provides azeotrope or azeotrope-like compositions including trifluoroiodomethane (CF3I) and 1,1,1,2,2,3,3-heptafluoropropane (HFC-227 ca), and a method of forming an azeotrope or azeotrope-like composition comprising the step of combining 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane (CF3I) to form an azeotrope or azeotrope-like comprising 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane (CF3I) having a boiling point of about −24.46° C. ±0.30° C. at a pressure of about 14.40 psia±0.30 psia.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.62/745,678, filed October 15, 2018, which is herein incorporated byreference in its entirety.

FIELD

The present disclosure is related to azeotrope or azeotrope-likecompositions and, in particular, to azeotrope or azeotrope-likecompositions comprising trifluoroiodomethane (CF3I) and1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca).

BACKGROUND

Fluorocarbon based fluids have found widespread use in industry in anumber of applications, including as refrigerants, aerosol propellants,blowing agents, heat transfer media, gaseous dielectrics, and firesuppression.

However, certain compounds such as chlorofluorocarbons (CFCs) andhydrochlorofluorocarbons (HCFCs) are suspected of depleting atmosphericozone and, thus, are harmful to the environment. Moreover, some of thesecompounds are believed to contribute to global warming. Accordingly, itis desirable to use fluorocarbon fluids having low or even zero ozonedepletion potential, such as hydrofluorocarbons (HFCs), or those with aphotolyzable carbon iodine bond, which exhibit short atmosphericlifetime when released at ground level. The use of single componentfluids or azeotrope mixtures, which do not fractionate on boiling andevaporation, is also desirable.

Unfortunately, the identification of new, environmentally-safe,non-fractionaing mixtures is complicated due to the fact that azeotropeformation is not readily predictable.

The industry is continually seeking new fluorocarbon-based mixtures thatoffer alternatives, and are considered environmentally safer substitutesfor CFCs, HCFCs and HFCs in use today. Of particular interest are iodidecontaining compounds and other fluorinated compounds, which have lowozone depletion potentials and low global warming potentials. Suchmixtures are the subject of this disclosure.

Although iodide containing compounds are of great potential interest,the purification of iodide containing compounds such astrifluoroiodomethane (CF3I) has presented challenges, and techniques forthe removal of impurities from trifluoroiodomethane (CF3I) such as, forexample, trifluoromethane (HFC-23), are in constant demand. Therefore,separation techniques such as azeotropic distillation, for example,would be highly desirable.

What is needed are compositions and techniques that may be used toprepare iodide containing compounds, such as trifluoroiodomethane(CF3I), of high purity.

SUMMARY

The present disclosure provides azeotrope or azeotrope-like compositionscomprising trifluoroiodomethane (CF3I) and1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca).

It is well-recognized in the art that it is not possible to predict theformation of azeotropes, and the present inventors have discoveredunexpectedly that trifluoroiodomethane (CF3I) and1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) form azeotrope orazeotrope-like compositions.

The present disclosure provides a composition comprising an azeotrope orazeotrope-like composition comprising, consisting essentially of, orconsisting of effective amounts of 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and trifluoroiodomethane (CF3I).

The azeotrope or azeotrope-like composition comprises, consistsessentially of, or consists of, from about 13 wt. % to about 42 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), from about 18 wt. % toabout 37 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), from about23 wt. % to about 24 wt. % 1,1,1,2,2,3,3-heptaluoropropane (HFC-227ca)or about 23.74 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), andfrom about 58 wt. % to about 87 wt. % trifluoroiodomethane (CF3I), fromabout 63 wt. % to about 82 wt. % trifluoroiodomethane (CF3I), from about76 wt. % to about 77 wt. % trifluoroiodomethane (CF3I), or about 76.26wt. % trifluoroiodomethane (CF3I).

In other words, the azeotrope or azeotrope-like composition may comprisefrom about 13 wt. % to about 42 wt. % 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and from about 58 wt. % to about 87 wt. %trifluoroiodomethane (CF3I), or from about 18 wt. % to about 37 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 63 wt. % toabout 82 wt. % trifluoroiodomethane (CF3I), or from about 23 wt. % toabout 24 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and fromabout 76 wt. % to about 77 wt. % trifluoroiodomethane (CF3I), or about23.74 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and about 76.26wt. % trifluoroiodomethane (CF3I). The azeotrope or azeotrope-likecomposition may consist essentially of 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and trifluoroiodomethane (CF3I) in the above amounts, orconsist of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I) in the above amounts.

The azeotrope or azeotrope-like composition has a boiling point of about−24.46° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia.

In another form thereof, the present disclosure provides an azeotrope orazeotrope-like composition consisting essentially of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I), having a boiling point of about −24.46° C.±0.30° C. at apressure of about 14.40 psia±0.30 psia.

In a further form thereof, the present disclosure provides a method offorming an azeotrope or azeotrope-like composition comprising the stepof combining 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I) to form an azeotrope or azeotrope-likecomposition comprising, consisting essentially of, or consisting of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I). The azeotrope or azeotrope-like composition may have a boilingpoint of about −24.46° C.±0.30° C. at a pressure of about 14.40psia±0.30 psia.

In a still further form thereof, the present disclosure provides amethod of separating 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I), from a primary composition comprising1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), trifluoroiodomethane(CF3I), and at least one impurity, including the steps of: forming,within the primary composition, a secondary composition which is anazeotrope or azeotrope-like composition comprising, consistingessentially of, or consisting of effective amounts of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) where the azeotrope or azeotrope-like composition may have aboiling point of about −24.46° C.±0.30° C. at a pressure of about 14.40psia±0.30 psia; and separating the secondary composition from theprimary composition and the at least one impurity.

In the foregoing method, the forming step may comprise forming, within,the primary composition, a secondary composition which is an azeotropeor azeotrope-like composition comprising, consisting essentially of, orconsisting of from about 5 wt. % to about 50 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 50 wt. % toabout 95 wt. % trifluoroiodomethane (CF3I) and which may have a boilingpoint of about −24.46° C.±0.30° C. at a pressure of about 14.40psia±0.30 psia.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plot of temperature vs. weight percent1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) measured according toExample 1.

DETAILED DESCRIPTION

It has been found that 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca)forms homogeneous, minimum boiling azeotrope and azeotrope-likecompositions or mixtures with trifluoroiodomethane (CF3I), and thepresent disclosure provides homogeneous azeotrope or azeotrope-likecompositions comprising 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I). The azeotrope or azeotrope-likecompositions may consist essentially of 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and trifluoroiodomethane (CF3I), or the azeotrope orazeotrope-like compositions may consist of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I).

The present inventors have found experimentally that1,1,1,2,2,3,3-heptafluoropropane heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I) form an azeotrope or azeotrope-likecomposition.

An “azeotrope” composition is a unique combination of two or morecomponents. An azeotrope composition can be characterized in variousways. For example, at a given pressure, an azeotrope composition boilsat a constant characteristic temperature which is either greater thanthe higher boiling point component (maximum boiling azeotrope) or lessthan the lower boiling point component (minimum boiling azeotrope). Atthis characteristic temperature the same composition will exist in boththe vapor and liquid phases. The azeotrope composition does notfractionate upon boiling or evaporation. Therefore, the components ofthe azeotrope composition cannot be separated during a phase change.

An azeotrope composition is also characterized in that at thecharacteristic azeotrope temperature, the bubble point pressure of theliquid phase is identical to the dew point pressure of the vapor phase.

The behavior of an azeotrope composition is in contrast with that of anon-azeotrope composition in which during boiling or evaporation, theliquid composition changes to a substantial degree.

For the purposes of the present disclosure, an azeotrope composition ischaracterized as that composition which boils at a constantcharacteristic temperature, the temperature being lower (a minimumboiling azeotrope) than the boiling points of the two or morecomponents, and thereby having the same composition in both the vaporand liquid phases.

One of ordinary skill in the art would understand however that atdifferent pressures, both the composition and the boiling point of theazeotrope composition will vary to some extent. Therefore, depending onthe temperature and/or pressure, an azeotrope composition can have avariable composition. The skilled person would therefore understand thatcomposition ranges, rather than fixed compositions, can be used todefine azeotrope compositions. In addition, an azeotrope may be definedin terms of exact weight percentages of each component of thecompositions characterized by a fixed boiling point at a specifiedpressure.

An “azeotrope-like” composition is a composition of two or morecomponents which behaves substantially as an azeotrope composition.Thus, for the purposes of this disclosure, an azeotrope-like compositionis a combination of two or more different components which, when inliquid form under given pressure, will boil at a substantially constanttemperature, and which will provide a vapor composition substantiallyidentical to the liquid composition undergoing boiling.

For the purposes of this disclosure, an azeotrope-like composition is acomposition or range of compositions which boils at a temperature rangeof about −24.46° C.±0.30° C. at a pressure of about 14.40 psia±0.30psia.

Azeotrope or azeotrope-like compositions can be identified using anumber of different methods.

For the purposes of this disclosure the azeotrope or azeotrope-likecomposition is identified experimentally using an ebulliometer (Walas,Phase Equilibria in Chemical Engineering, Butterworth-Heinemann, 1985,533-544). An ebulliometer is designed to provide extremely accuratemeasurements of the boiling points of liquids by measuring thetemperature of the vapor-liquid equilibrium.

The boiling points of each of the components alone are measured at aconstant pressure. As the skilled person will appreciate, for a binaryazeotrope or azeotrope-like composition, the boiling point of one of thecomponents of the composition is initially measured. The secondcomponent of the composition is then added in varying amounts and theboiling point of each of the obtained compositions is measured using theebulliometer at said constant pressure.

The measured boiling points are plotted against the composition of thetested composition, for example, for a binary azeotrope, the amount ofthe second component added to the composition, (expressed as eitherweight % or mole %). The presence of an azeotrope composition can beidentified by the observation of a maximum or minimum boilingtemperature which is greater or less than the boiling points of any ofthe components alone.

As the skilled person will appreciate, the identification of theazeotrope or azeotrope-like composition is made by the comparison of thechange in the boiling point of the composition on addition of the secondcomponent to the first component, relative to the boiling point of thefirst component. Thus, it is not necessary that the system be calibratedto the reported boiling point of the particular components in order tomeasure the change in boiling point.

As previously discussed, at the maximum or minimum boiling point, thecomposition of the vapor phase will be identical to the composition ofthe liquid phase. The azeotrope-like composition is therefore thatcomposition of components which provides a substantially constantminimum or maximum boiling point, that is a boiling point of about−24.46° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia, atwhich substantially constant boiling point the composition of the vaporphase will be substantially identical to the composition of the liquidphase.

The present disclosure provides an azeotrope or azeotrope-likecomposition which comprises effective amounts of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) to form an azeotrope or azeotrope-like composition. As usedherein, the term “effective amount” is an amount of each componentwhich, when combined with the other component, results in the formationof an azeotrope or azeotrope-like mixture.

The present azeotrope or azeotrope-like compositions may consistessentially of combinations of 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and trifluoroiodomethane (CF3I), or consist of combinationsof 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I).

As used herein, the term “consisting essentially of”, with respect tothe components of an azeotrope or azeotrope-like composition or mixture,means the composition contains the indicated components in an azeotropeor azeotrope-like ratio, and may contain additional components providedthat the additional components do not form new azeotrope orazeotrope-like systems. For example, azeotrope mixtures consistingessentially of two compounds are those that form binary azeotropes,which optionally may include one or more additional components, providedthat the additional components do not render the mixture non-azeotropicand do not form an azeotrope with either or both of the compounds (e.g.,do not form a ternary or higher azeotrope).

The present disclosure also provides a method of forming an azeotrope orazeotrope-like composition by mixing, combining, or blending, effectiveamounts of, 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I). Any of a wide variety of methods known inthe art for combining two or more components to form a composition canbe used in the present methods. For example,1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) can be mixed, blended, or otherwise combined by hand and/or bymachine, as part of a batch or continuous reaction and/or process, orvia combinations of two or more such steps. Both1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) are commercially available and can be procured from severaldifferent vendors. The components can be provided in the requiredamounts, for example by weighing and then combining the amounts.

The azeotrope or azeotrope-like composition comprises, consistsessentially of, or consists of, from about 13 wt. % to about 42 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), from about 18 wt. % toabout 37 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), from about23 wt. % to about 24 wt. % 1,1,1,2,2,3,3-heptalurorpropane (HFC-227ca),or about 23.74 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), andfrom about 58 wt. % to about 87 wt. % trifluoroiodomethane (CF3I), fromabout 63 wt. % to about 82 wt. % trifluoroiodomethane (CF3I), from about76 wt. % to about 77 wt. % trifluoroiodomethane (CF3I), or about 76.26wt. % trifluoroiodomethane (CF3I). The azeotrope or azeotrope-likecomposition of the present disclosure has a boiling point of about−24.46° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia.

In other words, the azeotrope or azeotrope-like composition may comprisefrom about 13 wt. % to about 42 wt. % 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and from about 58 wt. % to about 87 wt. %trifluoroiodomethane (CF3I), or from about 18 wt. % to about 37 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 63 wt. % toabout 82 wt. % trifluoroiodomethane (CF3I), or from about 23 wt. % toabout 24 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and fromabout 76 wt. % to about 77 wt. % trifluoroiodomethane (CF3I), or about23.74 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and about 76.26wt. % trifluoroiodomethane (CF3I).

The azeotrope or azeotrope-like composition may consist essentially of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) in the above amounts, or consist of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) in the above amounts.

The azeotrope or azeotrope-like composition of the present disclosurehas a boiling point of about −24.46° C.±0.30° C. at a pressure of about14.40 psia±0.30 psia.

Stated alternatively, the azeotrope or azeotrope-like compositioncomprises, consists essentially of, or consists of, as little as about13 wt. %, about 18 wt. % or about 23 wt. %, or as great as about 24 wt.%, about 37 wt. % or about 42 wt. % 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca), or within any range defined between any two of theforegoing values, and the azeotrope or azeotrope-like compositioncomprises, consists essentially of, or consists of, as little as about58 wt. %, about 63 wt. % or about 76 wt. %, or as great as about 77 wt.%, about 82 wt. % or about 87 wt. % trifluoroiodomethane (CF3I), orwithin any range defined between any two of the foregoing values. In oneembodiment, the azeotrope or azeotrope-like composition comprises,consists essentially of, or consists of, about 23.74 wt. % and1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and about 76.26 wt. % oftrifluoroiodomethane (CF3I). The azeotrope or azeotrope-like compositionof the present disclosure has a boiling point of about −24.46° C.±0.30°C. at a pressure of about 14.40 psia±0.30 psia.

The present disclosure also provides a composition comprising theazeotrope or azeotrope-like compositions. For example, there is provideda composition comprising at least about 5 wt. % of the azeotrope orazeotrope-like composition, or at least about 15 wt. % of the azeotropeor azeotrope-like composition, or at least about 50 wt. % of theazeotrope or azeotrope-like composition, or at least about 70 wt. % ofthe azeotrope or azeotrope-like compositions, or at least about 90 wt. %of the azeotrope or azeotrope-like composition.

The azeotrope or azeotrope-like composition comprising, consistingessentially of, or consisting of effective amounts of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) disclosed herein may be used for separating impurities from1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and/or trifluoroiodomethane(CF3I). One impurity that may be present in trifluoroiodomethane (CF3I)is trifluoromethane (HFC-23).

The preparation of azeotropic or azeotrope-like compositions comprising,consisting essentially of, or consisting of effective amounts of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) allows separation techniques such as azeotropic distillation, forexample, to be used to remove impurities from trifluoroiodomethane(CF3I) to provide trifluoroiodomethane (CF3I) of high puritiy.

In one example, an azeotrope or azeotrope-like compositions comprising,consisting essentially of, or consisting of effective amounts of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) may be formed from a composition including one or both of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) together with one or more other chemical compounds other than1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I), such as impurities. Following the formation of the azeotrope orazeotrope-like composition, the azeotrope or azeotrope-like compositionmay be separated from the other chemical compounds by a suitable method,such as by distillation, phase separation, or fractionation.

In this manner, the present disclosure provides a method of separating1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) as an impurity from aprimary, crude composition of trifluoroiodomethane (CF3I) which includes1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) as an impurity togetherwith at least one additional impurity, including the steps of providinga primary composition of crude trifluoroiodomethane (CF3I),1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) as an impurity, and atleast one additional impurity, and subjecting the primary composition todistillation, for example, at conditions effective to form a secondarycomposition which is an azeotrope or azeotrope-like compositioncomprising, consisting essentially of, or consisting of effectiveamounts of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I), and separating the secondary compositionfrom the primary composition by a separation technique such as phaseseparation, distillation, or fractionation, for example. Thereafter, theprimary composition may be subjected to further separation orpurification steps to obtain purified trifluoroiodomethane (CF3I).

The following non-limiting Examples serve to illustrate the disclosure.

EXAMPLES Example 1 Ebulliometer Study

An ebulliometer was used to measure azeotrope and azeotrope-likecompositions of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I). The ebulliometer included a vacuum jacketedglass vessel which was sealed at the bottom and open to the atmosphereat the top. The top, or condenser jacket, of the ebulliometer was filledwith a mixture of dry ice and ethanol to attain a temperature of about−72° C., which is significantly lower than the normal boiling points of−16.16° C. for 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and −22.34°C. for trifluoroiodomethane (CF3I) at a pressure of 14.40 psia. In thismanner, it was ensured that all vapors in the system were condensed andflowed back into the ebulliometer such that the liquid and vapor phaseswere in equilibrium. A quartz-platinum thermometer with an accuracyof±0.002° C. was inserted inside the glass vessel and used to determinethe temperature of the condensed vapor corresponding to the equilibriumboiling point of the mixture. Boiling chips were used to assist withmaintaining a smooth boiling of the mixture in the ebulliometer.

The following procedure was used.

1. The quartz thermometer was immersed into a long dewar which containedan ice/water slurry and it was verified that the thermometer read 0° C.The dewar was deep enough so that at least ¾ the length of thethermometer shaft was immersed in the ice/water. The thermometerresistance was recorded in ohms.

2. The condenser jacket was loaded to ¼ full with ethanol. The condenserjacket was cooled by slowly introducing dry ice to avoid boiling overand/or splashing of the ethanol.

3. A known amount of trifluoroiodomethane (CF3I) or1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) was added to theebulliometer and brought to a vigorously refluxing condition. Thetemperature and atmospheric pressure were recorded using a barometerwith a temperature indicator.

The measurement was carried out in two steps. In a first step, about24.50 g of trifluoroiodomethane (CF3I) having a purity of 99.88 area %as determined by gas chromatography (GC) was first introduced to theebulliometer by weighing the container before and after the additionusing a balance having an accuracy of ±0.01g. The liquid was brought toa boil and the equilibrium temperature of the trifluoroiodomethane(CF3I) was recorded at the recorded barometric pressure. Then,1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) having a purity of 99.99area % as determined by gas chromatography (GC) was introduced in smallincrements into the ebulliometer and the equilibrium temperature of thecondensed liquid mixture was recorded.

In a second step, about 16.09 g of 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) having a purity of 99 area % as determined by gaschromatography (GC) was introduced to the ebulliometer by weighing thecontainer before and after the addition using a balance having anaccuracy of ±0.01g. The liquid was brought to a boil and the equilibriumtemperature of the 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) wasrecorded at the recorded barometric pressure. Then, trifluoroiodomethane(CF3I) having a purity of 99.88 area % as determined by gaschromatography (GC) was introduced in small increments into theebulliometer and the equilibrium temperature of the condensed liquidmixture was recorded.

Data from the above first and second steps was combined to complete thecomposition range data from 0 to 100 weight percent of each of the1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and thetrifluoroiodomethane (CF3I) presented below in Table 1, which shows aminimum in temperature which indicates that an azeotrope had beenformed, and this data is also presented in graphic form in FIG. 1. Thebubble point temperature of the mixture remained constant indicatingthat the mixture was azeotrope-like over a large composition range.

TABLE 1 Ebulliometer Study of CF₃I/HFC-227ca at P = 14.40 psia T (° C.)wt. % CF₃I wt. % HFC-227ca (+/−0.01° C.) (+/−0.1) (+/−0.1) −22.34 100.000.00 −22.46 99.59 0.41 −22.70 98.83 1.17 −23.36 96.12 3.88 −24.01 90.959.05 −24.22 87.01 12.99 −24.38 81.43 18.57 −24.46 76.26 23.74 −24.4468.52 31.48 −24.31 62.80 37.20 −24.10 57.37 42.63 −23.84 51.88 48.12−23.77 48.31 51.69 −23.49 42.35 57.65 −22.61 35.02 64.98 −22.13 29.7470.26 −21.35 19.71 80.29 −19.76 11.40 88.60 −17.80 3.94 96.06 −16.160.00 100.00

Example 2 Separation of Impurities

In this Example, a crude composition of trifluoroiodomethane (CF3I) isprovided, including 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) as animpurity, along with other impurities such as trifluoromethane (HFC-23).This composition is then subjected to distillation at conditionseffective to form and separate an azeotrope or azeotrope-likecomposition of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I) from the remainder of the composition. Theseparated azeotrope or azeotrope-like composition of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) is removed from the remaining crude composition oftrifluoroiodomethane (CF3I) as a light component. The remaining crudecomposition of trifluoroiodomethane (CF3I) is then subjected todifferent temperature and pressure conditions wherein the otherimpurities such as trifluoromethane (HFC-23) may be separated by furtherdistillation to obtain purified trifluoroiodomethane (CF3I).

Aspects

Aspect 1 is an azeotrope or azeotrope-like composition comprisingeffective amounts of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I).

Aspect 2 is the azeotrope or azeotrope-like composition of Aspect 1,comprising from about 13 wt. % to about 42 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 58 wt. % toabout 87 wt. % trifluoroiodomethane (CF3I).

Aspect 3 is the azeotrope or azeotrope-like composition of Aspect 2,comprising from about 18 wt. % to about 37 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 63 wt. % toabout 82 wt. % trifluoroiodomethane (CF3I).

Aspect 4 is the azeotrope or azeotrope-like composition of Aspect 3,comprising from about 23 wt. % to about 24 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 76 wt. % toabout 77 wt. % trifluoroiodomethane (CF3I).

Aspect 5 is the azeotrope or azeotrope-like composition of Aspect 4,comprising about 23.74 wt. % 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and about 76.26 wt. % trifluoroiodomethane (CF3I).

Aspect 6 is the azeotrope or azeotrope-like composition of any ofAspects 1 to 5, wherein the composition has a boiling point of about−24.46° C.±0.30° C. at a pressure of about 14.40 psia ±0.30 psia.

Aspect 7 is the azeotrope or azeotrope-like composition of any ofAspects 1 to 6, consisting essentially of1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I).

Aspect 8 is the azeotrope or azeotrope-like composition of any ofAspects 1 to 7, consisting of 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and trifluoroiodomethane (CF3I).

Aspect 9 is a composition comprising the azeotrope or azeotrope-likecomposition of any of Aspects 1 to 8.

Aspect 10 is the composition of Aspect 9, comprising at least about 5wt. % of the azeotrope or azeotrope-like composition.

Aspect 11 is the composition of Aspect 10, comprising at least about 15wt. % of the azeotrope or azeotrope-like composition.

Aspect 12 is the composition of Aspect 11, comprising at least about 50wt. % of the azeotrope or azeotrope-like composition.

Aspect 13 is the composition of Aspect 12, comprising at least about 70wt. % of the azeotrope or azeotrope-like composition.

Aspect 14 is the composition of Aspect 13, comprising at least about 90wt. % of the azeotrope or azeotrope-like composition.

Aspect 15 is a method of forming an azeotrope or azeotrope-likecomposition comprising the step of combining1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) to form the azeotrope or azeotrope-like composition comprisingeffective amounts of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I).

Aspect 16 is the method of Aspect 15, the method comprising the step ofcombining 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I) to form the azeotrope or azeotrope-likecomposition of any of Aspects 1 to 8.

Aspect 17 is a method of separating 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and trifluoroiodomethane (CF3I) from a primary compositioncomprising 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca),trifluoroiodomethane (CF3I) and at least one impurity, including thesteps of forming, within the primary composition, a secondarycomposition which is an azeotrope or azeotrope-like compositioncomprising effective amounts of 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and trifluoroiodomethane (CF3I); and separating thesecondary composition from the primary composition and the at least oneimpurity.

Aspect 18 is the method of Aspect 17, wherein the azeotrope orazeotrope-like composition is as defined in any of Aspects 1 to 8.

Aspect 19 is the method of Aspect 17 or 18, in which the separation iscarried out by at least one of phase separation, distillation, andfractionation.

As used herein, the phrase “within any range defined between any two ofthe foregoing values” literally means that any range may be selectedfrom any two of the values listed prior to such phrase regardless ofwhether the values are in the lower part of the listing or in the higherpart of the listing. For example, a pair of values may be selected fromtwo lower values, two higher values, or a lower value and a highervalue.

As used herein, the singular forms “a”, “an” and “the” include pluralunless the context clearly dictates otherwise. Moreover, when an amount,concentration, or other value or parameter is given as either a range,preferred range, or a list of upper preferable values and lowerpreferable values, this is to be understood as specifically disclosingall ranges formed from any pair of any upper range limit or preferredvalue and any lower range limit or preferred value, regardless ofwhether ranges are separately disclosed. Where a range of numericalvalues is recited herein, unless otherwise stated, the range is intendedto include the endpoints thereof, and all integers and fractions withinthe range. It is not intended that the scope of the disclosure belimited to the specific values recited when defining a range.

It should be understood that the foregoing description is onlyillustrative of the present disclosure. Various alternatives andmodifications can be devised by those skilled in the art withoutdeparting from the disclosure. Accordingly, the present disclosure isintended to embrace all such alternatives, modifications and variancesthat fall within the scope of the appended claims.

What is claimed is:
 1. A composition comprising an azeotrope orazeotrope-like composition consisting essentially of effective amountsof 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I).
 2. The composition of claim 1, wherein the azeotrope orazeotrope-like composition has a boiling point of about −24.46° C.±0.30°C. at a pressure of about 14.40 psia ±0.30 psia.
 3. The composition ofclaim 1, wherein the azeotrope or azeotrope-like composition consistsessentially of from about 13 wt. % to about 42 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 58 wt. % toabout 87 wt. % trifluoroiodomethane (CF3I).
 4. The composition of claim1, wherein the azeotrope or azeotrope-like composition consistsessentially from about 18 wt. % to about 37 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 63 wt. % toabout 82 wt. % trifluoroiodomethane (CF3I).
 5. The composition of claim1, wherein the azeotrope or azeotrope-like composition consistsessentially of from about 23 wt. % to about 24 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 76 wt. % toabout 77 wt. % trifluoroiodomethane (CF3I).
 6. The composition of claim1, wherein the azeotrope or azeotrope-like composition consistsessentially of about 23.74 wt. % 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and about 76.26 wt. % trifluoroiodomethane (CF3I).
 7. Acomposition comprising an azeotrope or azeotrope-like compositionconsisting essentially of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca)and trifluoroiodomethane (CF3I) and having a boiling point of about−24.46° C.±0.30° C. at a pressure of about 14.40 psia ±0.30 psia.
 8. Theclaim 7, wherein the azeotrope or azeotrope-like composition consistsessentially of from about 13 wt. % to about 42 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 58 wt. % toabout 87 wt. % trifluoroiodomethane (CF3I).
 9. The composition of claim7, wherein the azeotrope or azeotrope-like composition consistsessentially of from about 18 wt. % to about 37 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 63 wt. % toabout 82 wt. % trifluoroiodomethane (CF3I).
 10. The composition of claim7, wherein the azeotrope or azeotrope-like composition consistsessentially of from about 23 wt. % to about 24 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 76 wt. % toabout 77 wt. % trifluoroiodomethane (CF3I).
 11. The composition of claim7, wherein the azeotrope or azeotrope-like composition consistsessentially of about 23.74 wt. % 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and about 76.26 wt. % trifluoroiodomethane (CF3I).
 12. Thecomposition of claim 7, wherein the azeotrope or azeotrope-likecomposition consists of from about 13 wt. % to about 42 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 58 wt. % toabout 87 wt. % trifluoroiodomethane (CF3I).
 13. The composition of claim7, wherein the azeotrope or azeotrope-like composition consists of fromabout 18 wt. % to about 37 wt. % 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and from about 63 wt. % to about 82 wt. %trifluoroiodomethane (CF3I).
 14. The composition of claim 7, wherein theazeotrope or azeotrope-like composition consists of about 23.74 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and about 76.26 wt. %trifluoroiodomethane (CF3I).
 15. A method of forming an azeotrope orazeotrope-like composition comprising the step of combining1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) to form an azeotrope or azeotrope-like composition consistingessentially of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I) having a boiling point of about −24.46°C.±0.30° C. at a pressure of about 14.40 psia ±0.30 psia.
 16. The methodof claim 15, wherein the combining step comprises combining from about13 wt. % to about 42 wt. % 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca)and from about 58 wt. % to about 87 wt. % trifluoroiodomethane (CF3I).17. The method of claim 15, wherein the combining step comprisescombining from about 18 wt. % to about 37 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 63 wt. % toabout 82 wt. % trifluoroiodomethane (CF3I).
 18. The method of claim 17,wherein the combining step comprises combining about 23.74 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and about 76.26 wt. %trifluoroiodomethane (CF3I).
 19. A method of separating1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and trifluoroiodomethane(CF3I) from a primary composition comprising1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), trifluoroiodomethane(CF3I) and at least one impurity, including the steps of: forming,within the primary composition, a secondary composition which is anazeotrope or azeotrope-like composition consisting essentially ofeffective amounts of 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) andtrifluoroiodomethane (CF3I) having a boiling point of about −24.46°C.±0.30° C. at a pressure of about 14.40 psia ±0.30 psia; and separatingthe secondary composition from the primary composition and the at leastone impurity.
 20. The method of claim 19, wherein the forming stepcomprises forming, within the primary composition, a secondarycomposition which is an azeotrope or azeotrope-like compositionconsisting essentially of from about 13 wt. % to about 42 wt. %1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and from about 58 wt. % toabout 87 wt. % trifluoroiodomethane (CF3I) and having a boiling point ofabout −24.46° C.±0.30° C. at a pressure of about 14.40 psia ±0.30 psia.